As a type of refrigeration cycles using a rotating machine such as a compressor or an expander, a refrigerating apparatus using the Brayton cycle is known. Examples of such a type of refrigeration system include a refrigeration system having a plurality of compressors or expansion turbines arranged in series on a circulation path in which the refrigerant flows to compress or expand the refrigerant in multiple stages thereby to improve the cooling capacity, as disclosed in Patent Document 1 or Patent Document 2.